Political philosophy for both Aristotle and Plato was of reasonable concern. One's character, virtues, vices, desire and especially education were relevant to determine a correct system of government. They both opposed relativism, scepticism as well as individualism in sophism (which was gaining popularity at that time) equally both Plato and Aristotle were opposed to democracies (to varying degrees) and more so for Aristotle; monarchies and aristocracies. However they both agreed governments and politics are both crucial fundamental characteristics of mankind. With Plato taking a more Oligarchical/Totalitarian approach by suppressing the individual and emphasizing what one is born with and their limiting capabilities deduced from that. Whereas Aristotle a much more progressive thinker, valuing the individual and protracting the promise of virtue and intelligence beyond what one starts out with, and more focusing on what one can become. I will first discuss Plato's idea of ideal politics, then Aristotles concluding with a comparison.
For Plato politics must be based on the study of human nature. He wanted a well ordered society, based mainly upon reason and logic. It was the ideal city of Plato that consisted of the four virtues of wisdom, moderation, courage and justice. It needs wisdom to have a wise city, bravery from courage against rivalling cities, justice for control of the masses and instilling the differences between right and wrong, as well as moderation; in that each role throughout society is shared, that each understands their role or as he puts it: "harmony that results when everyone is actively engaged in fulfilling his role and does not meddle with that of others" (Plato 85)
Plato said that the soul is in three parts; desire, spirit and reason. It was these three ideas he based his Plutocracy on. Plato's tripartite class structure involved the three classes; productive, protective and governing. The productive or 'desire' class contained workers of trades, farmers and merchants. These citizens were considered the least intelligent and less educated than the rest, and therefore delegated the task of the easiest and least intellectual difficulty. The protective section of society Plato calls the 'guardians' are essentially the armed forces or protectors of the city. The governing rulers are the intelligent, rational, self-controlled, wise (knowledge of the Good or 'right relations' between all that exists) the leader of this group Plato labels is the 'Philosopher-King'.
For Plato only philosophers had the correct attributes to govern the people. Only the philosopher king would know the best for the city and its members, he should be the one making the decisions. However on the contrary Aristotle believes that the city should be governed by many and through laws. For Aristotle; laws represent all that is reasonable and just, he disagreed that the many should be controlled by one. However these laws should still be created by the most intelligent of people.
"Until philosophers rule as kings or those who are now called kings and leading men genuinely and adequately philosophise, that is, until political power and philosophy entirely coincide, while the many natures who at present pursue either one exclusively are forcibly prevented from doing so, cities will have no rest from evils,... nor, I think, will the human race." (_Republic_ 473c-d)
Plato does not simply make open claims about who should and should-not rule the people. According to Plato we can't have true knowledge of things in constant change. Plato believes wholly in reason, through justifications of _a priori_ like mathematics and 'the forms' he contrasts these concepts with previous involvements through the senses Plato defines as 'dark' and 'dreary' compared with ideas. Virtue is something both Plato and Aristotle value...